Trouble with Algae

[HootingSloth]

I am new to pool ownership (moved in six weeks ago) so still coming up the learning curve. When we moved in, our pool was dark green/black due to neglect of the previous owner. A pool company helped us get things to clear blue water, but we have had recurring issues with algae returning, which I believe is mustard algae. They also helped us convert to a SWG. About a week ago, I got a Taylor k-2006c test kit and began following instructions for SLAMing the pool. At first, there were consistent improvements in the amount of algae each day. However, for the past two days I have not noticed any further improvements. We probably have only about 10% of the amount of algae as we started with before the SLAM, but it is still a decent amount building up on the floor of the pool between brushings. I tried increasing the chlorine levels somewhat (our CYA is at 30 ppm, our FC was at around 13 ppm earlier, and is now at around 18 ppm) with no additional results. We have a 27k gallon pool and a sand filter. I would appreciate any advice and whether I should just keep going with the SLAM despite the stall in improvements. Thank you.

 

[PoolStored]

Keep going with SLAM. No need to 18ppm. It's about maintaining and duration, not level above SLAM. Stay with 12 as your target.

Check everything and scrub...lights, ladders, trim around stairs, weir doors, main drains, behind lights, in skimmers...everything.

Likely not mustard.

You will get better faster results if you can check and replace FC every 1-3 hours.

Backwash the filter. Note pressure. When it rises 25%, backwash again.

Welcome to TFP!!!